How does a tumor develop?
The kidney is formed from special embryonic tissue, which normally is completely transformed into mature organ structures by the time of birth. If parts of it remain, they can become a source of tumor: such remains are called nephrogenic. Wilms tumor grows inside the kidney, pushing aside and squeezing normal tissue; it is usually enclosed in a capsule and does not extend beyond its boundaries for a long time. This is why it can reach large sizes without causing pain. Less commonly, the tumor affects both kidneys - such cases require special tactics with maximum preservation of renal tissue.
- Source: immature embryonic kidney tissue
- Growth within the kidney with displacement of normal tissue
- Long-term absence of pain
- Can reach significant sizes
- In some cases, both kidneys are affected
- Spread most often to the lungs and lymph nodes
Causes and risk factors
Most often, a tumor occurs for no apparent reason, and it is impossible to prevent it. However, there is a group of children with an increased risk in whom nephroblastoma occurs much more often: these are children with congenital syndromes accompanied by excessive growth of the body or its individual parts, with congenital absence of the iris, with developmental anomalies of the genitourinary system, as well as those who have already had such cases in the family. For such children, the pediatrician prescribes regular kidney ultrasounds in the first years of life, which makes it possible to detect a tumor very early.
- Congenital overgrowth syndromes
- Absence of the iris
- Anomalies of the development of the genitourinary system
- Familial cases of Wilms tumor
- Regular ultrasound of the kidneys in children at risk
- In most cases the cause is unknown
Symptoms
The main and most common symptom is a dense formation in the abdomen, which parents discover by chance. It is usually painless, does not move when breathing and is located on one side. At the same time, the child remains active for a long time and feels good, which often lulls his vigilance. Additional signs include abdominal pain, blood in the urine, increased blood pressure due to compression of the renal vessels, less often fever, pallor and decreased appetite. A sharp increase in pain with an increase in temperature may indicate hemorrhage into the tumor.
- Dense painless formation in the abdomen
- Increased abdominal volume
- Blood in urine
- High blood pressure
- Abdominal pain and vomiting
- Pallor and decreased appetite
- The general condition remains satisfactory for a long time
Diagnostics
The examination begins with an ultrasound of the kidneys and abdominal cavity, which is informative and safe in children: it shows the origin of the tumor from the kidney and allows it to be distinguished from tumors of other origins. Next, a CT or MRI is performed to assess the extent, condition of the second kidney, and the presence of tumor thrombi in the renal vein and inferior vena cava. A CT scan of the chest is mandatory, as the lungs are the most common site of distant lesions. Laboratory tests require a general blood and urine test and indicators of kidney function. If a tumor is suspected, the abdomen is palpated as carefully as possible.
- Ultrasound of the kidneys and abdomen
- CT or MRI of the abdomen
- Evaluation of the renal and inferior vena cava
- CT chest
- General analysis of urine and blood
- Renal function indicators
- Gentle examination of the abdomen
Treatment and prognosis
Treatment is carried out according to international protocols and usually includes several courses of chemotherapy before surgery, which shrinks the tumor and reduces the risk of its rupture during surgery. Then the affected kidney is removed along with the tumor and surrounding tissue; in case of bilateral damage, they try to preserve the kidney tissue as much as possible. After surgery, treatment is continued taking into account the stage and histological type, adding radiation therapy if necessary. The results for this tumor are among the best in pediatric oncology, and a child with one healthy kidney grows and develops normally.
- Chemotherapy before surgery
- Removal of a kidney with a tumor
- Maximum tissue preservation in bilateral lesions
- Continuing chemotherapy after surgery
- Radiation therapy according to indications
- Observation with ultrasound and CT according to schedule
- Protecting the remaining kidney from injury and nephrotoxic drugs
